1. Field of the Invention
The present invention relates to an apparatus for operating an aerosol container to dispense a metered quantity of the container's contents and may advantageously be made to do so automatically and periodically.
Pressurized aerosol containers are widely used to store and dispense fluid products such as deodorizers, insecticides, germicides and the like. It is desirable to dispense certain of these products, for example deodorizers and insecticides, automatically and periodically to maintain a preferred concentration of the product in the environment.
These containers usually have a dispenser valve operated through a vertically acting valve stem that projects out of one end of the container. Both the dispensing valve and valve stem are urged outwardly to a normally closed position away from an open depressed position by a spring or other similar device. Accordingly, the dispenser valve is opened by depressing the valve stem and closed by releasing the stem.
There are two basic types of dispenser valves which are operated through valve stems as described above. One continuously dispenses the contents of the container as long as the valve stem is depressed. The other dispenses a single measured quantity of the container's contents each time the valve stem is depressed.
An actuator button, formed with a nozzle, is usually mounted on top of the valve stem. The nozzle directs discharge of the contents of the container and the actuator button provides a convenient means for depressing the stem.
2. Description of the Prior Art
Devices which automatically and periodically operate aerosol containers are presently known. For example, U.S. Pat. No. 3,739,944 (Rogerson) discloses a battery operated apparatus that includes a valve engaging element in the form of a cam driven through a reduction gear train by an electric motor. A timing circuit for periodically operating the electric motor is also disclosed.
A timed spray dispense which includes a lever that engages the actuator button of an aerosol container and is pivoted by a rotating timing cam is disclosed in U.S. Pat. No. 3,018,056 (Montgomery). An electric motor powered by alternating current is used to rotate the timing cam.
U.S. Pat. No. 3,779,425 (Werner) discloses a periodical dispenser for aerosol containers that maintains the dispenser valve of the container in an open position. The contents of the container are dispensed in metered fashion by separate valves in the apparatus.
Other apparatus which periodically actuate an aerosol container are disclosed in U.S. Pat. Nos. 3,543,122 (Klebanoff et al.) and 3,289,886 (Goldsholl et al.). The Klebanoff et al. device employs a DC motor to drive a gear which, in turn, is coupled to a valve actuator by an eccentric drive. The Goldsholl et al. device utilizes a DC motor to drive a cam through a reduction gear train. The cam is engaged by a cam follower that is coupled to a spring loaded valve engaging element.
Apparatus which include gearless drive assemblies that utilize a flexible band wound about a drum or drive shaft are described in U.S. Pat. Nos. 3,592,069 (Welch); 2,617,315 (McClelland); and 2,575,935 (Westerberg). However, none of these patents disclose a device for actuating an aerosol container.